Air-cooled pneumatic hammer



July 5 1927. 1,634,780

(2. H. HAESELER AAAAAAAAAAAAAAA TIC HAMMER Fild Oct. 2 1920 n W 5! g m \5 f a t E 1 $6 $3 1% 3 If. g N '-N 1 i w w ATTORNEYS.

Patented July 5, 1927.

UNITED STATES v 1,634,780 PATENT. OFFICE.

CHARLES E. HAESELER, OF PHILADELTHIA, PENNSYLVANIA.

AIR-COOLED PNEUMATIC HAMMER.

Application filed October 28, 1920. Serial 80. 419,018.

cylinder of the hammer becomes heated from contact with the hot rivets. This heat is 'in part communicated from the shank of the rivet set to the front end of thecylinder and such heating of the front end of the cylinder gradually increases. If this heating action increases to such an extent asto cause the cylinder to expand at its front portion, the bore of the cylinder will be contracted and the piston will stick.

In the operation of manually supported 0 pneumatic hammers in driving hot rivets it is necessary in order to properly manipulate the tool that the operator hold the front end of the c linder with one hand and the heating of t e front part of the cylinder under 2 rapid continuous work becomes so great as to burn the operators hands and renders it necessary for the operator to employ an insulating love and in some cases the heat is unbearable to the hand.

In pneumatic riveting hammers of the portabletype. adapted for manual manipu-' lat-ion, it is customary tohave the main exhaust of compressed air from the cylinder pass direct to the atmosphere at the rear end of the cylinder or to lead such exhaust to the atmosphere through ports and passages in the cylinder and the sleeve portion of the handle at the rear end of the cylinder. In riveting hammers constructed in this man- 40 ner the compressed air at its point of exhaust to the atmosphereexpands and causes a decided drop in its temperature and in some instances, for example, in cold weather, when the hammer is operated on outside construction work, the exhaust passages at their outlet from the cylinder freeze or tend to freeze thereby causing a choking and irregular action of the ammer piston and a loss of power and in some cases aeomplete sto page of the piston movement.

'50 overcome the above objectionable results in the operation of pneumatic hammers and with other objects in view which will hereinafter more fully a pear, my invention comprehends in its broa and generic scope a novel construction and arrangement of an air cooled pneumatic hammer wherein one is enabled to utilize and so direct the blast of cool air exhausted from the cylinder as to prevent the front end of the cylinder becoming heated to a degree unbearable to the hand of .the operator or to cause irregular action or stoppage of the reciprocating piston.

It further comprehends a novel construction of a hammer cylinder having means to 7 direct the exhaust air to the forward end of the cylinder.

It further comprehends a nbvel construction of a cylinder which is provided with radiating portions or ribs preferably extending longitudinall of thecylinder and subjected if so desired to the cooling action of the exhaust air.

It further comprehends a novel construction of a c linder having a novel arrangement of ex aust ports therein and a novel construction and arrangement of a sleeve which causes the air to exhaust at a desired place in proximity to the forward end of the cylinder.

Other novel features of construction and w advantage will hereinafter tailed description.

For the purpose of illustrating my .invention, I have shown in the accompanying drawings embodiments thereof which are atpresent preferred by me, since theseembodiments will be found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which my invention consists can be various! arranged and organized and that my invention is not limited to the precise arrangement and organization of these instrumentalities as herein shown and described.

Figure 1 represents, in longitudinal section, a pneumatic hammer, embodying my invention.

Figure 2 represents a section on of Figure 1.

Figure 3 tion, another embodiment of my invention.

Figure 4 represents a section on line H of Figure 3.

appear in the de- 10o line 2-2 represents, in longitudinal sec- I Figure 5 represents an endelevation of a is hammer embodying my invention. The handle is provided with a grasping portion 2 and with a sleeve 3 which is recessed to form a tapered socket 4 which extends throughout the greater part of the sleeve. 5 des1gnates a cylinder or barrel, the inner end of which is provided with a tapered portion 6 which is machined to fit the corresponding tapered socket 4 in the handle. The cylinder 5 is provided with a piston chamber 7 in which reciprocates a piston 9 having in the form illustrated a reduced extension or impact portion 10 at its forward end, such portion being adapted to impact against the shank of a working tool'11. The grasping portion 2 of the handle contains a manually controlled throttle valve mechanism 12 which controls the passage of motive fluid from the inlet 13 to the passage 14 which communicates with the chamber 15 of the main distribution .valve 16. The chamber 15 com.- municates by means of ports 17 with the valve chamber 18 in which is mounted a valve 19. The valve chamber 18 communicates by means of a passage 20 with the rear end of the piston chamber 7 and by means of a passage 21 with one or more passages 22 in free communication with the forward end of the piston chamber 7.

23 designates exhaust ports which, as shown in Figures 1 and 2, communicate with the piston chamber 7 intermediate its ends and with exhaust passages 24 wliichscommunicate with the atmosphere by means of the exhaust ports 25, it being seen from Figure 2 that I employ a number of these exhaust ports, eight of them beingshown in Figure 2, so that the exhaust air is distributed substantially around the forward end of the cylinder 5.

In the embodiments seen in Figures-3, 4

and 5,. the ports are formed in a similar manner to that seen in Figure 1, it being seen that the cylinder has formed in its outer periphery the slots 26 which communicate with the ports 23 and which discharge to the atmosphere through the ports 27. 28 designates a split sleeve which has a clampmg or other fit on the cylinder 5 which is turned down, as indicated at 29, to form the shoulders 30 and 31 against which the ends of the split sleeve 28 abut. It will be seen that in this embodiment the cylinder 5 can be turned down intermediate its ends to form a reduced diameter to receive the tem-.

mer it will'be understood to those skilledin the art that upon the manual manipulation of the throttle valve mechanism to move I its throttle valve into open position, thelive motive fluid entering the inlet 13 passes 1, the live motive fluid will pass through the passage 20 into the rear end of the piston chamber 7 to effect the forward movement or working stroke of the hammering piston 9.

As soon as the rear end of the piston 9 passes the ports 23, the live motive fluid in rear of the piston can pass to the atmosphere through the exhaust ports 23, exhaust passages 24 and exhaust ports 25 which are disposed around the forward end ofthe cylinder so that the exhaust air will have a cooling action on the cylinder and its temperature will be prevented from increasing to an objectionable degree.

When the valve 19 is in a position reversed to that seen in Figure 1, the live motive fluid can pass through the passage 21, passage 22 into the forward end of the piston chamber and acting against the forward end of the piston will cause the piston to move rearwardly. As soon as the shoulder in proximity to the forward end of the piston uncovers the ports 23, the motive fluld is free to exhaust to the atmosphere through such ports 23, passage 24 and ports 25,

The valve 19 is shifted from one POSltlOll to another as the pressure of live motive fluid on one side of the piston is decreased by the exhaust action thus causing a drop in pressure on one side or the other of the valve.

It will be apparent from the foregoing that in accordance with my present inventioIi, I provide means for discharging the exhaust air through and around the forward end of the hammer cylinder so that the forward end of the cylinder will be maintained at all times under working conditions in such condition that it can be readily grasped and manipulated by the operator.

It is of course to be understood that my present invention is not limited to any special type of pneumatic hammer but can be employed to advantage with any desired or conventional type of main distrlbut on valve mechanism, throttle valve mechan sm or hammerin piston, the invention residing more particularly in the construction of the barrel or cylinder.

The flutes or grooves contributing to form the walls of the exhaust passages are preferably about evenly distributed around the circumference of the cylinder and.form a series of heat absorbingand heat radiating portions or ribs which aid in dissipating the heating thatmay occur during the operation of the pneumatic tool.

I'have found in practice that very advantageous results are obtained by so constructmg the cylinder that heat radiating l a the features of advantage enumerated ficat n part' I vent on or sacrificingv any-of 1' advanta as.

v I claim as new and desire may/so and absorbing portions are-formed which preferably but not necessarily extend in a.

direction longitudinally of-th'e cylinder." It

is desirable-butnot essential to have the exhaust of motive fluid directed towards 'orinto the passa which the walls of the heat radiating portions contribute to form.

In accordance with my ifesent invention, 1' am enabled to overcome t e excessive heating of the cylinder of the pneumatic hammer so that the pneumatic hammer can be readily manipulated by the o rator.

It will now'be apparent t tI have devised a. new'and useful construction of an air cooled pneumatic hammer which emas desirable in the'statement of the invention-Zand'the above description, and while- I. ha;ve,,i'n the present instance, shown and preferred embodiments thereof whichgwill give in practicejq-sa'tisfactosy and reliable results, it 18 that such-embodiments are susceptible of modiin various-particulars without defrom the-sp1r1t-or' sco of the in- Having thus described'my, invention, w at to secure by Le t 'ters Patent,- is: q

-'1, In a pneumatic hammer, a cylinder having 'a' piston chamber,-:.a piston in said chamber, means'to COIltl'OlilIlOtiVB fluid to-' efl'ect the reciprocations of said piston, said cylinder being provided with a plurality of longitudinally extendingl exhaustgrooves distributed around its circumference to form a series of heat radiating-surfaces, and separate means surrounding the cylinder to cover the major portions of said-grooves. 12. A pneumatic hammer having a cylinc er into 1ts piston'chamberintermediateits ends and having longitudinally extending exhaust grooves in its periphery communicating with said rts, and a sleeve surrounding said cylln erto cover said grooves and 'dischar provided with exhaust -portsopening contributing with the cylinder to form exhaust p'assa dischargin' to the atmosphere near t e forward end of; the cylinder. 3. A pneumatic hammer, comprising a gylinder having apiston chamber, a piston or the piston chamber, means to Introduce live motive fluid into-:opposite ends of said piston chamber to effect the reciprocatory movements of said piston, exhaust ports opening into the piston chamber at its rear rtion and uncovered by the piston prlor to 1ts reaching the end of its. rearward stroke, and longitudinally extendin exhaust passages within the wall of sai cylinder com- 'municating 'with said ports, located at sub.

=in with said chamber, and a longitudinally spit sleeve surrounding the intermediate portion of said cylinder and covering the major portions of said rooves.

5. In a pneumatic ammer, a cylinder having a piston chamber/a. reciprocatory piston, a valve controlling admission of fluid to said piston chamber, exhaust ports opening-into the iston chamber at its rear portion and ex aust passages extending forfrom said ports 1n the wall of said ence to. cool'it, said exhaust passages bein of greater len h than the length of sai piston and disc phere.

CHARLES HAESELER.

er and spaced around its circumfer- V arging freely to the atmos- 0 

